The video released overnight shows the suspect walking in the area of 16 Street and 4 Avenue around 5 a.m. Wednesday, police said.

The suspect, seen wearing a ball cap and messenger bag, followed a 22-year-old woman from a subway stop where she got off the F train, reached under her skirt, groped her and then took off, according to police.

Investigators are hoping the surveillance video helps catch the suspect, but witnesses said police had him in custody and let him go.

Don Harrington said he heard the woman screaming and ran outside to help.

“I jumped out and yelled out the window and they were separating,” he said.

Harrington said he and another neighbor chased the man they believed to be her attacker, holding him until police arrived.

But they said when other neighbors brought the terrified victim over to identify him for police less than 15 minutes later, officers had already let the man go.

Police sources told CBS 2 that because the victim wasn’t there to immediately identify the suspect, the decision was made to take down his information and release him.

Residents are now questioning that decision in a neighborhood that’s seen as many as 20 similar sex crimes in the last two years with many that are still unsolved.

It’s not clear whether the man in the surveillance video is the same man witnesses said they caught. Police said the entire matter, including why officers on the scene let the man go, is under investigation.